1. Field of the Invention
The present invention relates generally to devices for obtaining soil samples from below the surface of the ground. In particular, the present invention relates to soil sampling systems that allow access to a portion of the soil core for headspace screening without violating the integrity of the remaining soil core, and soil sample containment devices used to protect soil samples after the samples are collected by the soil sampling system.
2. Description of the Related Art
Soil sampling systems are commonly used to obtain soil samples from below the surface of the ground. The collected soil samples are used to determine soil conditions prior to construction, to locate mineral deposits, to study chemical dissipation and residue, to determine the concentration of environmental contaminants, to investigate hazardous waste sites, and in other ways well known in the art.
Unfortunately, the equipment and methodology for collecting and preserving soil samples do not allow for consistent and accurate soil analysis. It is common practice to retrieve a soil sample from the subsurface via a soil sampler, remove the soil sample from the soil sampler, and place the sample in a separate container. During this process, the handling and exposure of the soil sample increases the loss of contaminants which may be contained within the soil sample.
The existing process involves a user taking a core section of soil, cutting open the tube, screening the whole length of the tube for contamination vapors, and if the contamination is not high, putting that core section aside and going on to the next one until the user finds the highest level of contamination. The user cannot be sure which one has the highest contamination until all of the cores have been screened. In the meantime, the exposed soil samples of the open cores are volatilizing and the integrity of the soil samples is deteriorating.
For accurate soil analysis, it is important that the sample be collected without disruption of the soil structure, that the sample not be subsampled, and that the sample is sealed in a manner to prevent leaks of contaminants around the seal. This is particularly difficult when soil is being tested for contamination by volatile organic compounds (VOC) because the VOCs tend to volatilize when exposed to air. The sample should be isolated from air to maintain substantially the same level and type of contamination as when the sample was first cored from the earth. The ideal soil sample is one that is representative of its origin in the subsurface.